feat: 金蝶冲销状态回写拆分独立定时任务并支持分批配置

- 新增KingdeeWriteOffResultTask独立调度（Nacos thirdParty.bfi.writeOffResult.*开关/cron），从付款结果任务第④步拆出
- BfiProperties新增writeOffResult配置：syncEnabled开关、queryBatchSize分批大小默认1000，冲销批量查询与批量落库共用
- 回写仅扫描已同步且未冲销的结算单，已冲销为终态不再复查
- kingdee_write_off_status列默认值改为unwrittenoff，存量已同步NULL数据回填未冲销
- 补充扫描数/防重键数/金蝶返回数/落库数关键日志，summary文案修正为待查未冲销结算单

doc/sql/transport/lqj/temp/06_blade_formal_settlement_kingdee_writeoff_20261030.sql

@@ -2,7 +2,7 @@
 -- 列名遵循 MyBatis-Plus 驼峰转下划线默认映射（kingdeeWriteOffStatus -> kingdee_write_off_status，kingdeeWriteOffTime -> kingdee_write_off_time）；
 -- 若存在早期脚本误建的旧列名 kingdee_writeoff_status / kingdee_writeoff_time 则先重命名，否则按缺失新增
 -- 结算单列表展示金蝶侧旧应付/应收单冲销状态：定时任务按 A102-4/A302-4 hadwrittenoff 批量回写，
--- 选单预检/重推闸门实时查询后顺带回写；NULL=未推送金蝶或尚未校验，unwrittenoff-未冲销，writtenoff-已冲销（部分冲销视同已冲销）
+-- 选单预检/重推闸门实时查询后顺带回写；默认 unwrittenoff-未冲销（金蝶单据在未冲销前即视为未冲销，避免首跑全量初始化回写），writtenoff-已冲销（部分冲销视同已冲销）
 
 -- ==================== kingdee_write_off_status ====================
 -- 旧列名重命名（早期脚本版本，不存在则跳过）
@@ -12,7 +12,7 @@ SET @old_col := (
     AND COLUMN_NAME = 'kingdee_writeoff_status'
 );
 SET @ddl_sql = IF(@old_col = 1,
-  'ALTER TABLE `blade_formal_settlement` CHANGE COLUMN `kingdee_writeoff_status` `kingdee_write_off_status` varchar(20) COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT ''金蝶冲销状态：unwrittenoff-未冲销 writtenoff-已冲销（NULL=未推送金蝶或未校验）''',
+  'ALTER TABLE `blade_formal_settlement` CHANGE COLUMN `kingdee_writeoff_status` `kingdee_write_off_status` varchar(20) COLLATE utf8mb4_general_ci DEFAULT ''unwrittenoff'' COMMENT ''金蝶冲销状态：unwrittenoff-未冲销（默认） writtenoff-已冲销''',
   'SELECT 1');
 PREPARE ddl_stmt FROM @ddl_sql;
 EXECUTE ddl_stmt;
@@ -21,7 +21,7 @@ DEALLOCATE PREPARE ddl_stmt;
 -- 缺失则新增（支持重复执行）
 SET @ddl_sql = (
   SELECT IF(COUNT(*) = 0,
-    'ALTER TABLE `blade_formal_settlement` ADD COLUMN `kingdee_write_off_status` varchar(20) COLLATE utf8mb4_general_ci DEFAULT NULL COMMENT ''金蝶冲销状态：unwrittenoff-未冲销 writtenoff-已冲销（NULL=未推送金蝶或未校验）'' AFTER `kingdee_fail_reason`',
+    'ALTER TABLE `blade_formal_settlement` ADD COLUMN `kingdee_write_off_status` varchar(20) COLLATE utf8mb4_general_ci DEFAULT ''unwrittenoff'' COMMENT ''金蝶冲销状态：unwrittenoff-未冲销（默认） writtenoff-已冲销'' AFTER `kingdee_fail_reason`',
     'SELECT 1')
   FROM information_schema.COLUMNS
   WHERE TABLE_SCHEMA = DATABASE()
@@ -32,6 +32,13 @@ PREPARE ddl_stmt FROM @ddl_sql;
 EXECUTE ddl_stmt;
 DEALLOCATE PREPARE ddl_stmt;
 
+-- 存量已同步结算单回填默认未冲销（可重复执行：仅补 NULL 行；未同步单据保持默认值即可，前端按同步状态展示'-'）
+UPDATE `blade_formal_settlement`
+SET `kingdee_write_off_status` = 'unwrittenoff'
+WHERE `kingdee_write_off_status` IS NULL
+  AND `kingdee_sync_status` = 'synced'
+  AND `is_deleted` = 0;
+
 -- ==================== kingdee_write_off_time ====================
 -- 旧列名重命名（早期脚本版本，不存在则跳过）
 SET @old_col := (